Astrolium's cazimi calculator finds the exact windows when any classical planet sits in close conjunction to the Sun, distinguishing cazimi (within 17 arcminutes), combust (17 arcminutes to 8°30′), and under-the-beams (8°30′ to 15° or 17° depending on tradition). The tool accepts a target planet (Mercury through Saturn or Moon), a date range, an orb tradition (Lilly, Bonatti, or modern), and optional flags for new moons and solar eclipses. Output returns enter-orb, exact, and exit-orb timestamps to one-second precision in both UTC and local timezone, with orb at peak, ecliptic latitude, retrograde state, inferior-conjunction status, and a true-cazimi badge when the planet also sits within 17 arcminutes of ecliptic latitude. Practitioners use it for electional astrology when timing actions that require solar fortification (Mercury cazimi for signing, Jupiter cazimi for expansion) or avoidance of combustion. Calculations use a brentq root-finder against the Swiss Ephemeris. Free, no account required.
The heart of the Sun
Lilly mentioned cazimi only once in Christian Astrology (Bk 1, p. 113), but the line is exact: a planet within seventeen arcminutes of the Sun is "in the heart of the Sun," and "as one in the King's presence." Bonatti, writing four centuries earlier, gave a geometric reading of sixteen arcminutes, matching the Sun's apparent radius. Both authors treat the window as a moment of solar dignity, not damage. The planet five minutes outside that orb is combust; the planet five minutes inside is fortified.
The orb is narrow. For an inner planet like Mercury moving at one degree of separation per hour from the Sun, the cazimi window lasts about ninety seconds. Astrologers who write about cazimi without a precise calendar are guessing. This calculator publishes those windows with one-second timestamps in your local timezone.
Cazimi, combust, under the beams
The three Sun-proximity conditions in classical astrology form concentric rings:
| Condition | Orb (modern) | Orb (Lilly) | Reading |
|---|---|---|---|
| Cazimi | ≤ 17′ | ≤ 17′ | Fortified — in the King's presence |
| Combust | 17′ to 8°30′ | 17′ to 8°30′ | Severely debilitated — burnt |
| Under the beams | 8°30′ to 15° | 8°30′ to 17° | Partially weakened — invisible to glare |
The calculator returns every event in the date range, tagged with its condition and the exact orb at the moment of peak. The "true cazimi" badge appears when the planet is also within seventeen arcminutes of ecliptic latitude, which some practitioners require for the strongest reading.
Use cases by planet
Mercury cazimi. Favourable for writing, signing contracts, recording courses, sending the long-deferred email. The cazimi window during retrograde (inferior conjunction) is the synodic seed-point of the next Mercury cycle and is often used for reset-style elections.
Venus cazimi. Favourable for proposals, art reveals, gestures of reconciliation. Like Mercury, Venus has rare inferior-conjunction cazimi moments where the planet crosses the solar disk geometrically (the calculator flags these as "solar transit").
Mars cazimi. Rare and brief. Favourable for decisive actions that need an obvious moment: a launch, the first cut of surgery, an opening move. Combustion either side is a flag against elective action.
Jupiter cazimi. Long-duration matters: major life decisions, signing a multi-year contract, beginning a publication. Jupiter cazimi recurs roughly once a year.
Saturn cazimi. Annual. Useful for elections that require structure: incorporation, long-term commitments, building foundations.
Reading the events list
Each event row reports the planet, the condition badge, the exact moment (local and UTC), the orb at peak, and the planet's ecliptic latitude. Retrograde state and inferior-conjunction status are flagged inline. The footer of the row gives enter-orb, exact, and exit-orb timestamps so you can plan around the full window.
Group by month for long ranges. Filter by tradition to compare how the event count shifts. Lilly's wider under-beams orb produces noticeably more under-beam tags than the modern preset.
Why one-second precision matters
The orb-boundary refinement in the engine uses a brentq root-finder against the Swiss Ephemeris. For an inner planet sweeping through cazimi at four degrees of solar separation per day, the 17-arcminute boundary takes about 100 seconds to cross. A calculator that rounds to the nearest minute can mistime an election by half the window. The endpoint returns enter and exit timestamps to the second; that is the precision practitioners need for serious electional work.
Related tools
- Horary calculator — for a single question chart with Lilly's seven considerations.
- Electional search — for finding optimal moments by activity.
- Void of course calculator — for screening the Moon's state before an election.
- Essential dignities — for the dignity scoring framework cazimi sits inside.